The F85 is the X5 M of the F15 generation, 2015 to 2018: twin-turbo V8, four-wheel drive, and a chassis trying to make two and a half tonnes behave like rather less.
As with every M SUV of that era, the base car carries one F code and the M version another — F15 becomes F85, F16 becomes F86. Those two digits are the only thing separating the models in a parts catalogue, and they get mixed up routinely.
In body terms the F85 brings flared wings front and rear, its own bumpers with larger intakes, its own sills and a vented bonnet. Doors, roof and both halves of the split tailgate come from the F15.
The four tailpipes and the rear apron that accommodates them are M-specific. Cabin-wise, expect M seating, an M wheel and M dials on top of a standard X5 — the switchgear and electronics never changed.
